When comparing Flume vs Rocana, the Slant community recommends Flume for most people. In the question“What are the best log aggregation & monitoring tools?”Flume is ranked 15th while Rocana is ranked 16th.

Specs

Ranked in these QuestionsQuestion Ranking

Pros

Pro

Flume is transactional (no lost when duplicating streams), and can be backuped by Kafka

Pro

Hadoop integration

Flume was created to efficiently move log data to Apache Hadoop's HDFS.

Pro

Free and open source

Licensed under Apache 2.0.

Pro

Great "out-of-the-box" analytics

Beyond simple rules-based alerting, Rocana Ops creates statistical models for each of the metrics you want to track and evaluates as data streams in to provide nearly instantaneous feedback on how your systems are performing. Unique WARN (Weighted Analytic Risk Notifications) Scores indicate components that are trending to the good or bad. Users can create custom metrics, which get evaluated just the same as "out-of-the-box" metrics.

Pro

Highly scalable

Collect and analyze multiple TBs of data per day, built on Hadoop components Rocana Ops is a highly-distributed system offering massive scalability using commodity hardware. Rocana has customers collecting 10+ TBs of log data per day.

Rocana One free option provides up to 1TB of daily data volume for free.